DOS/interrupt.s at main · PythonCoders45/DOS · GitHub

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globalsyscall_stub
externsyscall_handler

section .text

syscall_stub:
pushad ; Save EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI

 ; Pass arguments from registers to C syscall handler
pushedx ; Argument 2
pushecx ; Argument 1
pusheax ; Syscall Number
call syscall_handler ; Call C dispatcher function in idt.c
addesp,12 ; Clean up pushed arguments from stack

popad ; Restore general purpose registers
iretd ; Return from interrupt (Restores CS, EIP, EFLAGS)